Hypovitaminosis D is associated with increased parathyroid hormone secretion,increased bone turnover, osteoporosis, histological osteomalacia and increased risk of hip and other fractures, and, in its most severe expression,clinical osteomalacia. These patients have been given high doses of both oral vitamin D2 and vitamin D3 supplementation without an improvement in vitamin D status due to poor intestinal absorption . Standardized treatment of vitamin D deficiency in most healthy individuals is achieved by giving vitamin D2 50,000 IU once a week for few weeks and then daily supplementation with lower doses. In the investigators Intestinal rehabilitation clinic, these patients are vitamin D insufficient or deficient while on large replacement doses of vitamin D2/D3 with some taking 200,000 IU daily.